“An important subject which needs to be addressed. Very worrying long term effects in the environment. We all need to do our bit and use these judiciously.”
“A very important subject, that needs to be discussed. Flea and tick products need to be regulated.
I have been looking into oral products Isoxazolines, as they are being widely used in Denmark, where I work (Afoxolaner, Fluralaner, Lotilaner, Sarolaner). As there is no environmental impact assessment, I would avoid the longer acting product, as it needs to be given at a much higher concentration to work for at least 3 months, but again it is not known which of the Isoxazolines are most harmful to the environment. For Fluralaner adequate immediate efficacy against fleas and ticks was achieved following oral administration of doses as low as 0.3 mg/kg bodyweight, persistent effect against fleas was demonstrated for 6, 12, and 14 weeks following administration of oral doses of 0.3, 1.25, and 5 mg fluralaner/kg. The strength of the tablets are at least 25mg/Kg (up to 56mg/Kg) to make sure of a persistent effect against ticks. So insects are being subjected to very high concentrations of fluralaner in the environment from pets faeces and to a lesser extent urine/hair and skin. For all of the Isoxalines the concentration needed to kill fleas are much lower than the concentration needed to kill ticks, so insects are being exposed with the use of these products. The monthly products can at least be used at a monthly and not three monthly interval, so treatment, if deemed necessary, can more easily be reduced to the shortest necessary time frame (and again the European Medicines Agency report does not supply us with any information about how long these products are excreted for). Also important is the route of excretion, where almost all of the Afoxolaner and Fluralaner are excreted in the faeces (vs respectively 0.01 to 0.001% via urine), but no information on metabolites. For Lotilaner it is stated renal clearance is less than 10% of the dose, again faeces being the major route of excretion. For Sarolaner it is only stated, that the primary route of elimination is biliary excretion (so faeces) of the parent molecule, with minor contributions from metabolic clearance. Isoxazolines are also quantifiable in hair and skin. So I am now informing owners of the possible adverse effects on the environment (here pesticide free/bee and butterfly friendly gardens are very popular and the general public are unaware that their pets, if treated, are a source of pesticides) and to pick up and dispose of faeces in the section of waste that is burnt over here. This is of course much more difficult or impossible with free roaming cats. It is also worth noting, that for several of the Isoxazolines the European Medicines Agency state "ticks and fleas must attach to the host and commence feeding in order to be exposed to the active substance, therefore the risk of the transmission of parasite-borne diseases cannot be excluded". In general I would not recommend topical products as a preventative treatment, as even cats and dogs being out in the rain will contaminate the environment with neonicotinoids and I agree dogs should not be allowed to bathe if treated with a spot-on product for at least a couple of weeks after the recommended treatment interval. If owners are alerted to the risk to the environment with the pesticides we use, I am sure many would use them less. More importantly regulation of the use of these products are needed and quickly.
Thank you for a great webinar.”
